A numerical model for the dynamic simulation of a recirculation single-effect absorption chiller

A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film evaporator–absorber, uses mixed recirculation and is exclusively cooled by the ambient air. Heat and mass transfer in the evaporator–absorber and in the desorber are described according to a physical model for vapour absorption based on Nusselt’s film theory. The other heat exchangers are handled using a simplified approach based on the NTU-effectiveness method. The model is then used to analyze the chiller response to a step drop of the heat recovery circuit flow rate, and to a sudden reduction of the cooling need in the conditioned space. In the latter case, a basic temperature regulation system is simulated. In both simulations, the performance of the chiller is well represented and consistent with expectations.

► Dynamic simulation of a new recirculation single-effect H2O/LiBr absorption chiller is developed.
► The chiller is driven by two heat sources and exclusively cooled by the ambient air.
► Heat and mass transfer in the absorber and the desorber are described according to a detailed physical model.
► Analyse of the dynamic behaviour of the chiller after sudden changes in operation.