VC-21A-C048 - Effect of Lowering Condenser Water Temperatures in the Chiller Efficiency

In water condenser systems, the designers usually use cooling towers to reject the heat absorbed in the condensed water from the system. Analyzing the diagram PxH, tells that as lower as the temperature of the water in the entering of the condenser, generate greater efficiency of the chiller due to the reduction in the lift of compression. However, to reduce the temperature of condensed water, the tower needs a higher electric consumption, generating a trade off in the condenser system. Thermal simulations, proved that for psychometric conditions of Denver, a system operating with higher demand in the cooling tower, the saving electricity can be superior to 5 times, when compared to the standard operation. In this way, a CWP with 1758 kW (500 tons) centrifugal chiller, operating during 2600 hours/year, can become an electric economy of up to USD $41 thousand/year, taking into account the thermal comfort conditions. In other words, the higher demand of the cooling tower saves energy in the CWP, because the chiller is grater consumer in the system. By evaluating the simulation in other regions, it selects results and guarantees the different local psychometric conditions.