The Gas District Cooling (GDC) plant at Universiti Teknologi PETRONAS (UTP) is
responsible for supplying chilled water to the main campus, where it is used as the source of
chilled water for air conditioning. Current operations at GDC, electric chillers (EC) are used
to charge the Thermal Energy Storage (TES) at night and then discharge the chilled water
during the day to support chilled water requirements during peak period. Steam Absorption
Chiller (SAC) operation is to supply the chilled water during the day and not during
operation at night. However, this practice does not take the advantage of 24 hours operation
of gas turbine that produced waste heat. This project is focus on using the SAC to charge the
TES tank during night to support EC in order to optimize the use of waste heat. A two-stage
charging is proposed. Current configuration is charging the TES tank from 5 p.m. to 7 a.m.
only by EC. The proposed wo-stage configuration, the TES tank is charged by SAC as the
first stage to cool the chilled water from l3°C to 9°C, then, the second stage is charged by
EC to cool the chilled water from 9°C to 6°C. The time of the both charging process is
maintained from Sp.m. to 7a.m. The operation of two-stage based on one SAC in operation
and three EC's in operation
