DSC approach and estimation of the solid fraction of a CO2 hydrate slurry in flow in an experimental loop applied to secondary refrigeration

Abstract : The present work investigates the suitability of CO2 hydrate for a use as phase change material in two-phase secondary refrigeration. Unlike the generation of the classical two-phase refrigerants, power limited by mechanical parts, hydrate slurry production has the advantage of being performed using a nonmechanical process. Nevertheless, in order to be efficient, it needs to fulfil two major conditions: a high latent heat of melting of the solid phase and appropriate flowing conditions of the slurry. Consequently, in a first part, multi-cycle DSC (Differential Scanning Calorimetry) measurements were performed and confirmed a value of CO2-hydrate dissociation enthalpy of approximately 500 kJ.kgH2O-1, one and a half higher than that of ice (333 kJ.kgH2O-1). In a second part, an experimental loop made it possible to study the CO2 hydrates in suspension in a carrying liquid and estimate the solid fraction of the slurry.