Enhancing Thermal Management in Microfluidic Heat Exchangers Through the Integration of Nano-Encapsulated Phase Change Materials

Abstract Efficient thermal management is crucial in microfluidic heat exchangers operating under high heat flux conditions. This study evaluates a copper microfluidic heat exchanger enhanced with nano-encapsulated phase change materials (NEPCMs), comprising a paraffin core enclosed in silica shells. The NEPCM exhibited a particle size of 78 ± 2 nm, a thermal conductivity of 0.55 W/m·K, and a latent heat capacity of 199.3 J/g, confirmed through DSC and thermal conductivity measurements. Experiments were performed using deionized water at flow rates ranging from 10 to 50 ml/min with an inlet temperature of 298 K. The incorporation of NEPCM significantly strengthened the system’s thermal management capability, reducing thermal resistance from 0.83 K/W to 0.57 K/W (31.3% improvement) and increasing the heat transfer coefficient from 1,360 W/m2·K to 1,845 W/m2·K (35.7% enhancement) at 30 ml/min. Importantly, the outlet temperature decreased from 308.7 K to 302.0 K—a 6.7 K drop—while temperature fluctuations during transient loading were reduced by 13.2%, demonstrating improved cooling effectiveness and thermal stability. A CFD model was subsequently developed in ANSYS Fluent and validated using the experimental measurements, with deviations within 4%, confirming the reliability of the numerical framework. Overall, the results highlight the strong potential of NEPCMs to enhance heat dissipation, stabilize operating temperatures, and improve the thermal management performance of compact microfluidic systems used in electronics cooling and lab-on-chip applications.