Flow and heat transfer characteristics of microencapsulated phase change material slurry in horizontal tubes.

Thermal or cold storage in refrigeration and air-conditioning systems is a promising way to alleviate the peak-valley difference of the electricity load. The thermal or cold storage by phase change material slurry is one of the good measures to be implemented in refrigeration and air conditioning systems. In the present study, we numerically investigate the flow and heat transfer characteristics of micro-encapsulated phase change material slurry (MPCS) in straight tubes under constant wall heat flux. The solid-liquid two-phase nature of micro-encapsulated phase change material slurry is properly taken into consideration in the theoretical modeling. And the comparison of the numerical results to the experimental results is carried out to validate the theoretical modeling. It is found that the imhomogeneity presents in the case of horizontal tube due to the effect of the gravity. And the heat transfer characteristics of micro-encapsulated phase change material slurry can be classified into different regions, in which different heat transfer mechanisms are elucidated.