| Popis: |
This study is focused on the performance evaluation of a water-cooled chiller. Exergy analysis of a water-cooled chiller was carried out in order to identify the contributions of individual components to the total exergy destruction. The second law efficiency of each component as well as the exergetic efficiency of the chiller were assessed. Data were taken at two-hour intervals (six readings daily) for thirty days. Data obtained from the chiller inventory records include suction and discharge pressure and temperature of the refrigerant in the compressor, as well as temperature and mass flow rates of cooling water and chilled water. Other properties of the refrigerant were obtained from ammonia property table. From the results obtained, the compressor was identified as the largest contributor to exergy destruction (about 59% of the total exergy destruction in the chiller), the evaporator contributed about 16%, the condenser contributed 20% while the throttle valve contributed the least to exergy destruction (5%). It was ascertained that the evaporator has the highest second law efficiency of 70.29%, while the efficiencies of the compressor and condenser were 60.01% and 36.09%, respectively. The average exergetic efficiency of the chiller was found to be 35.10%. The overall results reveal that the potential capacity of the chiller remained unutilized. Measures to improve the performance indices and overall efficiency of the chiller have been suggested in this study |
