Power Density of Silica Nano-Holed Microcapsule Composites Based on Calcium Chloride for Chemical Heat Pump

抄録

The hydration characteristics of calcium chloride/silica microcapsule composite cell have been investigated. Especially, this paper focused on the effect of encapsulation ratio of calcium chloride in microcapsules and gap fraction of composite cell on power density of composite cell based on hydration reaction experiments. The mass of sodium polymethacrylate (Na-PA) in the microcapsule generation process was changed for controlling the encapsulation ratio. The gap fraction of the cell was also controlled by the concentration of sodium silicate used for bonding material between microcapsules. From the results, it was found that thermal storage density of composite cells when the gap fractions of cells were set constant at 0.69 could optimize the power density of cell, which reached 0.52 kW/L when the encapsulation ratio of calcium chloride was 69.9 wt%. It was also revealed that the reaction rate is not severely affected by the encapsulation ratio. When the encapsulation ratio of calcium chloride was at 69.9 wt%, the power density increased with the increasing gap fraction from 0.64 to 0.71 and reached 0.56 kW/L at 0.71. It showed that low gap fraction hindered the penetration of water into cell and reduced the hydration reaction rate.