OCEAN THERMAL ENERGY CONVERSION TECHNOLOGY

OCEAN THERMAL ENERGY CONVERSION TECHNOLOGYPresent a source of energy which is the son of the sun and ocean.
OTEC is an energy that converts solar radiation into usable energy.
Ocean thermal energy conversion or OTEC can produce a significant
amount of power because of the difference between the warm surface
of sea water and the deep cold ocean water.

The oceans cover a little more than 70 percent of earths surface.
This makes it the world''s largest solar energy collector and energy
storage sytem.

On an average day,60 million square kilometers of tropical seas absorb
an amount of solar radiational equal in heat content to about 250 billion
barrels of oil.

OTEC, Ocean Thermal Energy conversion is an energy technology that converts
solar radiation to electric power.
The oceans are thus a vast renewable resource, with potential to help us
produce billions of watts of electric power.

The cold seawater used in the OTEC process is also rich in nutrients and it
can be used to culture both marine organisms and plant life near the shore
or on land.
The idea behind OTEC is the use of all natural collectors,thesea,instead of
artificial collector.

Warm water is collected on the surface of the tropical ocean and pumped by
a warm water pump. The water is pumped through boiler, where some of the
water is used to heat the working fluid, usually propane or some similar
material.If it is cooler you can use a material with a lower boiling point
like ammonia.
The propane vapour expands through a turbine which is coupled to a generator
that generating electric power.
Cold water from the bottom is pumped through condensers,where the vapour
returns to the liquid state. The fluid is pumped back into the boiler.

There are two different kinds of OTEC power plants, the Land based and the
floating plant.

Land - based power plant : The land based pilot plant will consist of
a building. This building will contain the heat exchangers,turbines,
generators and controls.
It will connected to the ocean via several pipes, and an enormous fish
farm (100 football arenas) by other pipes.
Warm water is collected through a screened enclosure close to the shore.
A long pipe laid on the slope collects cold water. Power and fresh water
are generated in the building by the equipment.
Used water is first circulated into the marine culture pond (fish farm)
and then discharges by the third pipe into the ocean, downstream from the
warm inlet.
This is done so that the outflow does not reenter the plant, since re-use
of warm water would lower the available temperature difference.

Floating power plant : works in the same way as the land based the apparent
difference is that the floating plant is floating.

Closed - cycle, open -cycle and hybrid - cycle : - There are three types of
OTEC designs: open cycle,closed cycle, and hybrid cycle.
In an open cycle, seawater is the working fluid. Warm seawater is pumped into
flash evaporator where pressure as low as 0.03 bar cause the water to boil
at temperatures of 22 centigrades. This steam expands through a low pressure
turbine connected to a generator to create power.The steam then passes
through a condenser using cold seawater from the depths of the ocean to
condense the steam into desalinised water.

In a closed cycle, a low boiling point liquid such as ammonia or another
type of refrigerant is used as the working fluid in a Rankine cycle
(common steam cycle).
The heat from warm seawater flowing through an evaporator vaporises the
working fluid.
The vapour expands through a turbine, and then flows into a condenser
where cold seawater condenses it into a liquid.