Dynamic modelling of secondary refrigeration loop with CO2 hydrate slurry.

Secondary refrigeration is an often used solution to reduce the amount of refrigerant leakage and the impact of refrigerants on global warming. The use of two-phase fluids in refrigeration systems is known to increase the quantity of stored energy. In this work, the impact of gas hydrates on the energy release of a heat exchanger is quantified thanks to the dynamic modelling of a secondary refrigeration system. The system is composed of a chiller, a stirred tank reactor (hydrate formation), a loop and a heat exchanger (hydrate dissociation). The model validated by experimental data can be used to simulate various operating conditions in transient and permanent regimes (various slurry mass flow rate, various thermodynamic conditions) and to compare their energy performances. The numerical and experimental results showed better heat exchanger efficiency with hydrate slurry than with water alone.