Modelling and optimisation of absorption system operation. Application to a real installation

We present the dynamic modelling of an absorption system and an application to a large air-conditioned system. This study was performed using the ALLAN.Simulation software, a pre- and post- processor enabling the symbolic description of systems. The absorption system is a direct gas double effect absorption chiller or heater, using LiBr/HB2BO as working fluid. This modelling has two aims. The first one is to optimize the water circuit by determining the volume of a storage tank that maximise the energetical and economic operation performances. The second objective is to evaluate by simulation the influence of the previous results on a large air-conditioned system and over given periods. We describe the modelling approach and the results are compared with measurements monitored during summer 1994. The models created are available for use by engineers for sizing, optimizing or doing economic evaluation of HVAC systems.