Specific cooling power intensification limits in ammonia–carbon adsorption refrigeration systems

A conceptual model for a sorption refrigeration system based on a plate-type sorption generator using monolithic carbon and ammonia is suggested. The system is simulated in a finite-difference model that accounts for heat and mass transfer resistances, fluid heat transfer coefficients, etc. Mass permeability does not appear to be a limitation on specific cooling power (SCP) in the range tested. It was found that there is a limit to the minimum heat transfer fluid channel thickness in order to prevent the pumping power required from becoming too large relative to the cooling power provided. It should be possible to construct a monolithic carbon–ammonia refrigeration system utilising a simple non-regenerative cycle with a COP typically about 0.3 and SCP better than 2000 W kg−1 carbon. The design is based on a 2 mm thick carbon layer with 0.2 mm stainless steel plates and 0.5 mm thick fluid channels.