ocean thermal energy convertion
Post on 16-Apr-2017
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Presentation
by
Rakib Hossain
ID: 11.02.08.047
What is ocean thermal energy conversion (OTEC) Temperature difference between cooler deep &
warmer surface to run a heat engine and produce electricity.
Distance between surface & cooler deep should be 1000m.
Mainly rankine cycle is used in the process .
Refrigerants used- ammonia or R-134a .
Ocean thermal energy conversion
Process of OTEC
Cycles in OTEC >>>
Open cycle
Close cycle
Hybrid cycle
Open cycleWarm surface water is used directly.
First surface water is pumped for boiling.
Produced steam drives to turbine connected to generator.
Steam is condensed by the cold temperature from deep water.
closed cycle
Closed cycle
•Uses fluid with low boiling point.•Surface water pumped by heat exchanger to vaporize fluid.•Fluid vapor turns the turbo generator.•Vapor condensed by the flow of cold water by 2nd heat exchanger.
Hybrid cycleCombination of closed & open cycle.
Evaporation is same as open cycle.
Working fluid vaporized as closed cycle.
Vaporized fluid drives turbine.
Working fluid
Popular choice – ammonia >> easy availability >> but toxic & flammable.
Fluorinated carbon – CFC or HCFC >> not toxic or flammable >> destroy ozone layer.
Hydrocarbons >> highly flammable .
Thermodynamic efficiency
Temperature difference between surface and deep water is high in tropic , helps to run heat engine.
It is 10 to 100 times more efficient than wave power of ocean.
It can supply continuous base load supply to power generation system.
It is considered as emerging technology.
Evolution of OTEC
1880 >> 1st attempt to develop OTEC . 1930 >> 1st OTEC plant built in Cuba . (22 kw) ,
destroyed by storm later . 1967 >> 1st use of closed cycle of rankine
system . Japan is the major contributor of OTEC since
1970. 2002 >> OTEC plant in tamilnadu , India. OTEC plant is increasing day by day .
Different types of OTEC sites
Land sites >>near sea shore Advantages >> do not need { sophisticated mooring,
long cable, extensive maintenance} Shelf based >>Far from surf zone, near to cold water.Disadvantages >> difficult product delivery, long cable
needed, more expensive. Floating sites >>Operate off shore, optimal for large system.Disadvantage >> complicates power delivery , possibility
of damage of cable, difficult to maintain & repair.
Related activities other than power generation Air conditioning
Chilled soil agriculture
Hydrogen production
Producing distilled water
Aqua culture
irrigation
Figure of related activities other than power generation
Cost & Economics It is a renewable energy .
One study shows that its cost is US $ 0.07 per kilowatt –hour.
Beneficial fact : lack of waste products and fuel consumption.
Supplemental use of sea water.
Many more useful fact other than power generation.
Environmental impact
Carbon dioxide dissolve
Unbalance ecological system
Accidental condition of closed cycle
Effect in commercial fishing
Conclusion
We need 6500 MW electricity per day , but we are producing only 5500 MW .As it’s a low cost harmless renewable energy to produce electricity , it could be bless for our country.
For more info please visit ;www.OTEC.org
Thank you all
Any question??
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