Experimental study of an ammonia-water absorption chiller

This paper presents the performance of an ammonia-water absorption chiller. This single-stage 10 kW absorption chiller is cooled with a water-ethylene glycol solution. The required heat source is hot water between 75 °C and 85 °C. Different operating conditions can be imposed by varying temperatures and flow rates of secondary circuits and the flow of the rich solution. This equipment, designed for solar air conditioning applications, was tested under various operating conditions to assess its performance. This study shows that the performance of the absorption chiller decreases significantly with the evaporator temperature. This is due to a problem of partial evaporation in the evaporator when the absorption machine is operated outside its design specifications. Cooling capacity oscillations, caused by refrigerant expansion control, were also observed. Absorption chiller performance is also influenced by heat source temperature, cooling temperatures and flow of the rich solution.