Author(s)

Takehiro Esaki^*, Noriyuki Kobayashi

Department of Chemical Engineering, Nagoya University, Nagoya, Japan.

Here, we propose a chemical heat pump chiller with a SrBr₂ hydration reaction system for utilization of waste heat. The SrBr₂ hydration reaction could recover waste heat in low temperatures ranging from 373 K to 353 K, and the system showed good potential in terms of the high cooling thermal-storage density. Previous studies have given little information on the reaction characteristics of the SrBr₂ hydration reaction. In this paper, we developed a measuring method for the hydration reaction equilibrium and reaction rate based on the volumetric method. We analyzed the hydration reaction rate with an unreacted-core shell model. In the experiments, the SrBr₂ equilibrium temperature observed was equal to the theoretical equilibrium temperature obtained from thermodynamic databases. In addition, the hysteresis gap between the hydration and dehydration values was 2.0 K. Thus, the hysteresis effect was negligible for the chemical heat pump cooling operation. The reaction fraction of the SrBr₂ hydration reached 0.7 within 20 s. By analyzing the hydration reaction rate with the unreacted-core shell model, the activation energy value was calculated to be56.6 kJ/mol. The calculation results showed good agreement with those of the experiment as the reaction fraction reached 0.7.

Chemical Heat Pump, SrBr₂ Hydration, Hysteresis, Unreacted-Core Shell Model

Esaki, T. and Kobayashi, N. (2016) Reaction Rate Characteristics of SrBr₂ Hydration System for Chemical Heat Pump Cooling Mode. Journal of Materials Science and Chemical Engineering, 4, 106-115. doi: 10.4236/msce.2016.42012.