Numerical study on laminar convective heat transfer enhancement of microencapsulated phase change material slurry using liquid metal with low melting point as carrying fluid

摘要

The laminar convective heat transfer enhancement of microencapsulated phase change material slurry using liquid metal with low melting point as carrying fluid (MEPCM-LM slurry) in a tube with constant heat flux has been investigated numerically. The influence of each factor affecting the heat transfer enhancement was analyzed in detail by using an effective specific heat capacity model and considering axial heat conduction to be not neglected. Furthermore, the heat transfer ability of MEPCM-LM slurry was compared with that of MEPCM slurry using water as carrying fluid (MEPCM-Water slurry). It is found that bulk Stefan number and MEPCM concentration are the most important parameters influencing the heat transfer enhancement of MEPCM-LM slurry. The degrees of heat transfer enhancement increase with decreasing bulk Stefan number, dimensionless initial supercooling and/or dimensionless phase change temperature range, and increase with increasing mass concentration. The peak of the degree of heat transfer enhancement decreases with increasing Re. Moreover, the heat transfer ability of MEPCM-LM slurry is better than that of MEPCM-Water slurry, and the difference of the heat transfer ability for two slurries increases with decreasing x/r_0, therefore, it is more advantageous to heat dispersion of chip in narrow space for MEPCM-LM slurry.