Energy saving and environmental impact of optimizing the number of condenser fans in centrifugal chillers under partial load operation
Abstract In this paper, an optimization model is extended to optimize the coefficient of performance of refrigeration systems at partial load operation, based on optimal number of condenser fans. The sizes of vapor compression chillers are 703, 1266 and 1758 kW, and the number of fans varies from 1 to 6 while the ambient temperature ranges from 30 to 50 °C and partial load ranges from 0.25 to 1. Results show that the partial load where the optimized COP reaches its maximum value, ranges from 0.68 to 0.76 and decreases by increasing the size of chiller A correlation is proposed for partial load at which COP reaches its maximum value, as a function of nominal cooling capacity and outdoor ambient temperature. Finally, it is found that the average amount of 5.6 GWh/year electric energy saving and 5.1 ton/year CO2 emission reduction can be achieved by optimization of number of condenser fans.