RHEOLOGICAL STUDY OF AN HYDRATE SLURRY FOR AIR CONDITIONNING APPLICATION

Under atmospheric pressure condition and temperatures between 0°C and +12°C, Tetra-n-ButylAmmonium Bromide (TBAB) aqueous solutions crystallise into hydrate slurries. These slurries seems to be well appropriate for cold storage and transportation in the case of air-conditioning applications. We focus here on the crystallisation and the rheological properties of TBAB hydrates slurries. Once the crystallisation conditions described, we propose an experimental analysis of their flow behaviour. The experimental device is made up of a brushed surface heat exchanger in which the hydrates slurry is generated, and of a measurement loop. The flow behaviour of the slurry is characterised through flow rates and pressure drops measurements. We obtain flow curves of hydrates slurries depending on the volume fraction of hydrate solid particles. In the range of shear rate investigated, hydrate slurries behave as Bingham fluids. We propose a method of determining their apparent viscosities and yield shear stress versus the volume fraction of hydrates