Proposal and validation of a model for the dynamic simulation of a solar-assisted single-stage LiBr/water absorption chiller

In this paper, a general mathematical model for the dynamic simulation of a single-effect LiBr/water absorption chiller is presented. The model is based on mass and energy balances applied to the internal components of the machine, and it accounts for the non-steady behaviour due to thermal and mass storage in the components. The validation of the mathematical model is performed through experimental data collected on a commercial small-capacity water-cooled unit. Due to the peculiar technology adopted in the real chiller, a special effort was made to identify the appropriate values of the main physical parameters. The validation of the model is based on the values of the water temperature at the outlet of the machine, as no measurement inside the machine was possible; anyway, a consistency analysis applied to the internal parameters is also presented. The agreement between experimental and simulated results is very good, both on a daily and on a seasonal basis.

► Dynamic simulation plays a very important role in the study of the performance of an absorption chiller.
► The model proposed in the present paper applies to commercial solar-assisted LiBr/water absorption units.
► Its validation is performed by means of real daily operating data collected on an experimental unit.
► A consistency analysis is presented, based on the study of the response to a step variation in the driving temperature.
► The model is finally used to optimize the volume of the storage tanks installed in the experimental plant.