Air cycle cooling and heating Part II: a mathematical model for the transient behaviour of fixed matrix regenerators

This paper presents a mathematical model of a pair of fixed matrix regenerators employed as an autodefrosting device in an air cycle freezing and cooling plant. Measurements made on a pilot plant show that the model predicts the major characteristics correctly, in particular and most importantly, the autodefrosting characteristic. The conclusions are that the plant performance 'proves the concept' but further experimental work is needed to calibrate the regenerator model.