Experimental and Simulation Study of High-Efficiency Heat Storage Materials for Aerospace Applications

Abstract

To meet the stringent requirements of high heat transfer performance and lightweight nature for aerospace heat storage equipment (HSE), this paper incorporates fins into the phase change material (PCM) and conducts an optimization design through experiment and simulation. Utilizing n-eicosane for heat storage and aluminum alloy 6061 as the fin material, the objective is to devise an HSE for high-power heating elements, ensuring that the hot end temperature remains below 50°C and the weight is within 3.5 kg during the operational period. Heat sources of 50 and 100 W are, respectively, employed for experimental testing. The experiments reveal that when the heating power is 100 W, the temperature in the heat concentration region ascends to 43.2°C after a heating duration of 1900 s; in the scenario where the heating power is 50 W, the maximum temperature reaches 38.0°C after 3800 s of heating. The discrepancy between the simulation results and the experimental outcome is within 5%, thereby attesting to the relatively high accuracy of the simulation. Simulations were carried out with the thickness and number of fins as variables to analyze the heat transfer performance and weight of the HSE. The results show that within the research range, as the fin thickness increases, the overall heat transfer effect is enhanced. When the fin thickness increases at equal intervals between 1.0 and 3.0 mm, except for 3.0 mm, the hot end temperature of the HSE gradually decreases, and the weight also increases with the increase of the fin thickness. With the increase in the number of fins, the hot end temperature decreases, and the decrease in the hot end temperature is particularly significant at 13 fins. Considering the comprehensive influence of heat transfer performance, hot end temperature, and weight in this HSE, the structure with a fin thickness of 2.0 mm and 13 fins is the best. The volume ratio of the PCM in the HSE is between 0.55 and 0.60. According to the optimization results, an HSE with a total weight of 3.33 kg is processed. After using the optimized HSE with a heating power of 50 W continuously applied for 10,000 s, the hot end temperature is 42.17°C, which is 6.9°C lower than that of the HSE without fins, and the melting rate is increased by 46%. After a heating power of 100 W is continuously applied for 4000 s, the hot end temperature is 48.16°C, which is 13.2°C lower than that of the HSE without fins, and the melting rate is increased by 71%. In addition, the heat transfer performance of the HSE has been analyzed, and the change law of the heat transfer performance during the melting process of the PCM was found. This study will provide guiding ideas and reference significance for the research and development of enhancing heat transfer and lightweight of high-power HSE in aerospace.