Reallocation of adsorption and desorption times for optimisation of cooling cycles

摘要

In an adsorption cycle it is common to have an equal duration of the adsorption and desorption phases. In this paper, we investigated an intermittent cooling cycle with variable adsorption/desorption duration at fixed total cycle time. A new composite, LiNO_3/silica KSK (SWS-9L), was used as a water sorbent. It was specifically synthesised for adsorptive chilling units driven by low temperature heat (65-75℃). The sorption equilibrium and dynamics of SWS-9L were studied under conditions close to those realized in a typical cooling cycle. The actual performance of SWS-9L was tested in a single bed adsorption chiller with special emphasis on the optimisation of the relative duration of isobaric adsorption and desorption stages to maximize the Coefficient Of Performance and the Specific Cooling Power of the cycle. The tests resulted in being able to make practical recommendations to rationally optimise the relative duration of adsorption and desorption phases.