A modeling approach to evaluate the performance of a commercial absorption Chiller

Abstract

This study describes and analyses the performance of a commercial 3-ton ammonia/water absorption chiller under steady-state regime. A steady-state simulation model is developed and validated using the flow-sheeting software Aspen-Plus. First an appropriate thermodynamic property model from the software library for the ammonia/water system is tested. The interaction parameters of this model are determined by fitting the equation of state (eos) to VLE data. It is found that the Boston-Mathias modified Peng-Robinson eos with fitted parameters predicts accurately the VLE for the temperature and pressure ranges encountered in commercial chillers. A simulation model of the machine is then developed. The simulation results are found to be in good agreement with data from literature for 35°C cooling air temperature.