Another important improvement is the configuration of chilled
water mixed with part of chilled water back from users. In order to
reveal how the configuration saving energy, energy-utilization diagram (EUD) methodology is adopted. EUD analysis considers
energy transformation between an energy-donating process and
an energy-accepting process, and focuses graphically on the energy
level difference between a pair of energy donor and energy acceptor. The variations of both energy level and energy quantity are
graphically shown with ADH coordinates. The energy level A is
an intensive parameter and a ratio of exergy change (based on chosen reference condition) to energy change of a process (A = DE/
DH = 1T0DS/DH). The change of energy quantity (DH) refers to
any kind of energy changes, such as thermal energy, power consumption, or generation, and energy change in chemical reaction