Development of a high-thermal-storage composite material embedded with PCM microcapsules and analysis of its unsteady heat transfer process

Abstract

Phase-change insulation materials can effectively extend the holding time of submarine oil and gas pipelines. Shape-stable phase-change composites have good application prospects owing to their chemical stability and leakage resistance. In this study, a microencapsulated phase-change material (MPCM)-embedded polyurethane (PU) composite (PU–MPCM) was prepared as an insulation material for subsea pipelines. The unsteady heat transfer process of the PU–MPCM composite was simulated using COMSOL Multiphysics, and an insulation experiment was conducted on this composite. PU–MPCM exhibited a high thermal storage performance and favorable shape stability. The relative effective enthalpy coefficients of PU–MPCM composites with different MPCM contents were greater than 80%. The maximum MPCM content in the PU–MPCM composite was 24 wt% (PU–MPCM24). The melting enthalpy of PU–MPCM24 reached 35.95 J/g, and its effective thermal conductivity was as low as 0.16 W/(m∙K). The holding time of PU–MPCM24 could be increased by 229.79% compared with that of pure PU. The PU–MPCM composite exhibited good mechanical properties and low water absorption, making it suitable for underwater environments. Owing to its low-cost preparation process and excellent thermal properties, PU–MPCM24 can be considered a potential insulation material for practical applications in subsea pipelines.