Prototyping of a real size air-conditioning system using a tetra-n-butylammonium bromide semiclathrate hydrate slurry as secondary two-phase refrigerant – Experimental investigations and modelling

Among innovative processes developed in the field of refrigeration systems, technologies are encountered which are based on the application of Phase Change Materials (PCM) for the storage and transportation of energy. PCM are often provided by means of slurries. In the air-conditioning system presented here, a slurry of semi-clathrate hydrate crystals based on Tetra-n-Butyl-Ammonium Bromide (TBAB) is used as secondary refrigerant. The production of the slurry can be smoothed over day and night. Upon storage, the slurry can be distributed to end users, and melted to recover the cooling capacity. By adaption of a standard refrigeration technology, it is at first demonstrated that an air-conditioning system can be established by replacing the standard refrigeration fluid by a slurry of TBAB based semi-clathrate hydrate. Furthermore, the study attempts to model the settling of particles within the storage tank, aiming at gaining some insight in their complex migration processes obtained during the production and distribution steps.