Convective performance of encapsulated phase change material slurries of water, pao and engine oil in microchannels

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.

The performance of microencapsulated phase change material slurries of different base fluids inside microchannels is numerically investigated. The presence of phase change material increases the heat capacity of the fluid during melting. For the study, water, polyalphaolefin (PAO) and engine oil have been used as base liquids and n-octadecane has been used as phase change material and the performance at different concentrations flow parameters is analyzed. A microchannel of 600µm hydraulic diameter and 1 cm length was considered for the study and the 3D numerical simulations were performed using COMSOL. For the study, a heat flux of 50 W/cm2 is used for lower mass flow rate and 500 W/cm2 is used large mass flow rate. Effective heat capacity method was used to simulate the phase change behavior of PCM. Bulk properties of slurry were used assuming homogeneous distribution of PCM particles. The inlet temperature of the fluid was assumed to be at the 23 °C and the melting range of PCM is assumed to be 10 °C. The pressure drop and heat transfer characteristics were simulated and the comparison results for different cases are presented. It was found that the performance of the slurry was higher compared to its base fluid only under certain conditions.