Pre-cooling Technique for a Thermal Discharge from the Coastal Thermal Power Plant

The power plants are generally located along the coastline to meet their requirement of cooling water. The warm water discharge from the power plant is one of the major environmental concerns in view of the thermal pollution in the water bodies. The temperature limit for the warm water discharge from the thermal power plant, prescribed by the Ministry of Environment and Forest (MoEF) was 5oC before being discharged in to the water bodies. M/s. Bombay Suburban Electric Supply (BSES) Company Ltd. has established a thermal power plant at Dahanu, which is operating on ‘once-through’ cooling system and the cooling water is being drawn from Savta Creek. The temperature of condenser discharge was around 7.2oC. As such, a pre-cooling channel of 230m wide and 1800 m length was suggested through the hydraulic model studies to bring down the warm water temperature rise from 7.2oC to within the acceptable limit prescribed by the MoEF (i.e. 5oC) before being discharged in to the creek system.