Evaluation of the integrated performance for floor heating using micro-encapsulated phase change material slurry

Abstract

The micro-encapsulated phase change material (MPCM) slurry has the advantage of high heat transfer performance and heat capacity. Using MPCM slurry in the radiant floor heating (RFH) system could improve the indoor environment, but the overall performance was highly affected by heat transfer and pressure drop. In this paper, the flow and heat transfer model of MPCM slurry was developed and verified. The performance of serpentine and counterflow spiral structures was compared. Afterward, the optimized MPCM slurry material was selected as the heat transfer medium in RFH systems. Meanwhile, the flow and thermal performance of water and MCPM slurry were compared. Finally, the effects of different volume fractions and inlet velocities on integrated performance were investigated. The results indicated that the comprehensive performance of the serpentine system was better than the counterflow spiral. When the volume fraction was 15%, the comprehensive evaluation coefficients of three MPCM slurry heat systems are 17.9%, 22.9% and 13.8% higher than water respectively. MPCMS2 (n-dodecane) was suitable to use as the heat transferring medium in RFH system. Furthermore, as the volume fractions were 10%, 20% and 30%, the optimized velocities were 0.5 m s−1, 0.9 m s−1 and 1.1 m s−1, respectively.