Numerical analysis on the thermal behavior and optimization of a phase change cold energy storage device with thermoelectric coolers as a cold source

Abstract

Combining the advantages of phase change cold energy storage devices (PCCESDs) and thermoelectric coolers (TECs) is an effective method to efficiently utilize clean energy and reduce the mismatch between energy supply and demand. However, research on PCCESD using TEC as the cooling source is limited. In this paper, a novel PCCESD based on flat miniature heat pipe arrays utilizing TEC as the cooling source is numerically studied and optimized. The study examines the influence of fin structure and phase change temperature of the phase change materials (PCMs) on the device’s performance. Additionally, an orthogonal experiment method is employed to determine the optimal fin structure. Results show that increasing fin height and thickness, along with reducing fin spacing, significantly improves the cooling performance of the TEC and solidification rate of the PCM. Based on the results of orthogonal experiments, the optimal combination for the device’s fin structure includes a fin thickness of 0.1 mm, a height of 30 mm, and a spacing of 2 mm. Compared with the pre-optimization period, the COP of the TEC and solidification velocity of the PCM increase by 10 % and 1.8 %, respectively, but metal consumption only increases by 4.23 × 10⁻⁴ m³. Nonanoic acid with a phase change temperature of 12 °C is also identified as a suitable choice for the device. Under these conditions, the cooling power and COP of the TEC can further improve to 28.43 W and 0.385, representing increases of 60.9 % and 65.9 %, respectively.