Rheological and thermal study of a secondary refrigeration loop by hydrate slurry
Etude rhéologique et thermique d'une boucle de réfrigération secondaire par coulis d'hydrates
Abstract
Conventional refrigerant fluids are harmful to the environment due to their GWP and thus it is necessary to reduce their use. One of the solutions could be to employ secondary refrigerant fluids, such as CO2 hydrate slurry. In this context, the aim of this work is to carry out a rheological and thermal study on CO2 hydrate slurry. The experimental device is composed of a pilot loop in which the hydrate slurry is studied. Gas hydrates are formed under positive temperatures and pressures up to 3 MPa. Furthermore, the local and global heat transfer coefficients are also evaluated. Rheology revealed that slurry has a pseudo-plastic behavior between 0 % and 22 % of hydrate volume fraction. Thermal study showed that the slurry has a local heat transfer coefficient of around 3000 W.m-2.K-1 for 15 % of hydrate volume fraction. That value is higher than that of single phase water and slightly higher than the one of ice slurry. These results point out the strong potential of hydrate slurry for energy storage and transfer.