Effect of the Generator on the Performance of a Small Aqua-Ammonia Absorption Refrigeration System

The study aims at promoting the efficiency of a small aqua-ammonia absorption refrigeration efficiency and probing into the things that the component of system affects the system。In the experiment, the heater provides 6 kW, 6.5 kW, 7 kW, 8 kW and 9 kW to the aqua-ammonia solution within the generator. The controlled variables are the fan frequency of the condenser, the temperature and the flow rate of water/glycol solution, and the cooling water flow rate.
The result shows that the cooling capacity increases with increasing generator heat transfer. The coefficient of performance (COP) of the system increases when the quantity of the generator heat transfer is increased from 6 kW to 7 kW, however it decreases in the range of 7 kW-9 kW. When the fan frequency increases, the temperature of liquid ammonia leaving condenser decreases, while the cooling capacity and the COP of the system increases. When the flow rate and inlet temperature of water/glycol increases, the evaporator takes more heat away and the cooling capacity and COP of the system increases.
If the heat provided by the generator maintains constant during the experimental process, the absorber has the most affect on the performance of the generator. When the temperature of ammonia leaving absorber decreases, induced by increasing the flow rate of the cooling water, the concentration of aqua-ammonia to the generator increase, but the temperature of ammonia entering the generator decreases（the generator temperature decreases.）. When the flow rate of cooling water through the absorber is at 7 to 8 L/min, the system provides the highest cooling capacity and the coefficient of performance (COP).