Abstract:
Cooling tower is crucial piece of equipment for any refinery as it is used to reject
waste heat. It operates on the principle of heat and mass transfer and cools water on
the mechanism of evaporation. Cooling water system has a wet-cooling tower which
provides cooling water to heat exchangers in parallel. Our project aims to reduce both
energy and water consumption by replacing three existing cooling towers with one,
along with devising an efficient exchanger network. For the design of the tower
Merkel’s Method is used through which an enthalpy –temperature diagram is
constructed and used to find the number of stages. Manually designed cooling tower
was simulated on Aspen Plus to find out the targeted relative humidity. Packed bed
sand filter was used to purify the blowdown stream and centrifugal pumps installed
in different streams. For the optimization of heat exchanger networks Aspen Energy
analyzer was used which gave the least possible heat transfer area further utilized to
calculate the purchase cost of equipment.
