In oceans, a temperature difference of 200 C exists between deep cold water and surface warm water. The warm surface heats and vaporizes low billing liquid like ammonia (NH3) or 1,1,1,2 tetras luoroethane ( R-134a)
The increased the pressure of the liquid drives the turbine gets condensed by cold deep water situated at a depth of about 1000m. the liquid is pumped to vaporized to start the cycle again india piloted a 1-MW floating ocean thermal energy plant near Tamil Nadu.
Uses of ocean thermal energy
- Ocean thermal energy conversion system can provide air-conditioning to buildings closer to the plants.
- It is used to generate electric power.
- It is used for chilling agriculture products.
- It is used for producing hydrogen.
- It is used for maintaining the temperature of water for aquaculture.
Limitations of ocean thermal energy
- The efficient heat exchanger is required.
- Heat exchanger vaporizer condenser and turbines work under partial pressure for which proper sealing is required.
- The fluorinated working liquid function better but can deplete the ozone layer.
- Heat exchanger generally undergoes bio-fouling due to microbes present in sea \ ocean.