State of the art and kinetics of refrigerant hydrate formation

Abstract

This study aims to introduce suitable hydrate forming-refrigerants well-suited for air-conditioning systems through a kinetic study. The formation of clathrate hydrates is a time-consuming process. Hence, in an air-conditioning system, which uses refrigerant hydrate as a media for storage of cold energy, the knowledge of the hydrate formation rate, is crucial. In this experimental study, the rate of hydrate formation of four refrigerant blends, including R404A, R406A, R408A and R427A have been investigated. The induction time for hydrate formation, apparent rate constant of the hydrate reaction, water to hydrate conversion during hydrate growth, storage capacity, and the rate of hydrate formation of these refrigerants at various pressures and temperatures have been obtained using a kinetic model. The effect of sodium dodecyl sulfate (SDS) on the hydrate nucleation rate was also investigated. This study also aims to prepare a review on gas hydrates applications and characteristics in the power generation systems and cold storage applications including air conditioning systems. The advantages and disadvantages of this compound over traditional storage media and phase change materials (PCMs) including water, ice, salt hydrates, eutectic salts, paraffin waxes and fatty acids, slurries and phase changed emulsions have been reviewed.