A mathematical model was developed to describe both the hydrodynamic and heat transfer characteristics of the multi-compartment absorption heat transformer for dierent steam temperatures (the MAD transformer). Both the absorber and generator vessels are partitioned in a number of compartments which depend on the number of required high quality steams and available waste vapours, respectively. The absorber and generator components are modelled as a series of tanks. The ¯ashing of the solution which takes place between the absorber and generator is also included. The physical properties of the working pair are assumed to change with time and concentration throughout the transformer. Some of the model parameters, such as solution backmixing and gas dispersion, could be determined from experimental data.
The mathematical model derived is capable of predicting steady-state, transient, and dynamic behaviours of the transformer. Good agreement was obtained when the model responses were compared with the experimental data describing the hydrodynamic behaviour of the absorber. Transient and dynamic simulations showed that the heat transformer attains steady-state conditions within 40±60 min. This is an important feature since any further operational disturbances to the process, to which the is incorporated, should be minimized.