Experimental and numerical optimization of cascaded PCM heat sink by using low melting point alloys

Abstract

The effectiveness of cascaded phase change materials (PCMs) in improving the efficiency of latent heat storage systems has been widely proved. However, this heat transfer enhancement technique is seldom applied in the field of PCM-based thermal management. To improve the thermal management efficiency of PCM heat sink, a novel cascaded PCM heat sink with low melting point alloys is proposed. Firstly, three single PCM heat sinks and three cascaded PCM heat sinks are experimentally tested within a heat flux range of 1.0 to 3.0 W/cm2. Then, a simplified one-dimensional model is established to further analyze the enhancement mechanism of the cascaded PCMs. At last, the volume fraction of each PCM in the cascaded PCM heat sink is optimized by coupling the genetic algorithm and the numerical model. The experimental results prove that the application of the cascaded PCMs can improve the thermal management performance of the PCM heat sink effectively. Under the heat flux condition of 3.0 W/cm2, the maximum managed time of the cascaded PCM heat sinks is about 8.47 min, which is 7.2 % longer than that of the single PCM heat sinks. The configuration and volume fractions of PCM have a significant influence on the thermal performance of the cascaded PCM heat sinks. Though optimizing the volume fractions of each PCM, the managed time of the optimized cascaded PCM heat sink is further prolonged to about 8.88 min. The current study not only exhibits the application potential of the cascaded PCMs in electronic component cooling, but also provides guidelines for the design and implementation of cascaded PCM cooling systems for other cooling applications.