Performance analysis of an air conditioning system driven by natural gas

The performance data related to direct-fired double-effect water–lithium bromide absorption chillers in air conditioning systems are scarce. The knowledge of these data is important to validate the models that predict their performance, as well as to establish the design criteria and control strategies that lead to an optimal performance of these machines in air conditioning systems. The objectives of this work were to acquire and analyse the performance data of a 105 kW direct-fired double-effect water–lithium bromide absorption chiller, to simulate with TRNSYS the performance of an air conditioning system in which this machine operates, and to compare the recorded data with the results obtained from simulation. The use of a steady-state model to model the absorption machine predicted an energy consumption 30% lower than that registered at the air conditioning system. This difference was due to the effect of the transient performance of the absorption chiller, not considered by the employed model.