Abstract
In order to improve the energy performance of an existing district heating and cooling(DHC) system, retro-commissioning was analyzed using graphical simulation method and mathematical models, and improved operation schemes were proposed. The simulation results show that the energy comsumed by chiller and cooling tower can be reduced by 2.2% if the cooling water temperature set at an optimal value of 22℃. Becaouse the current return temperature of chiller water is lower than design value of 13.5℃, the simulation shows that the total energy consumption of the cooling plant can be reduced by 9.5% if the return temperature of chiller water could be kept at 13.5℃.
