WELCOME

CON

VERSION

Presented By :

Electrical DepartmentGroup No - 6

ASANSOL ENGINEERING

COLLEGE

SO WHAT EXACTLY OTEC IS Ocean Thermal Energy ConversionOTEC utilizes the world’s largest solar radiation collector - the ocean. The ocean contains enough energy power all of the world’s electrical needs.OTEC is a way to generate electricity using the temperature difference of sea water at different depth.

DISCOVERY

In 1881 Jacques Arsene d'Arsonval, a French physicist, was the first to propose tapping the thermal energy of the ocean.

In 1930 Arsonval built an experimental open cycle OTEC system at Matazas Bay, Cuba. The system produce 22 KW of electricity.

OTEC utilizes the ocean’s 20ºC natural thermal gradient between the warm surface water and the cold deep sea water(around 1 Km.) to drive a Rankine Cycle

WORKING PRINCIPLE

Oceans surface

waters acts as heat source and the

cold water at 1,000 meters

depth acts as heat sink.

OTEC PROCESS

OTEC PROCESS

2. Fluid pump pressurizes and pushes working fluid to evaporator

1. Power input to pumps to start

process

3. Heat addition from the hot-water source used to evaporate the working fluid within the heat exchanger (Evaporator)

EVAPORATOR

CONDENSER

WARM SURFACE WATER 28 C

4. Expanding vapor drive the turbine, and electricity is created by a generator

5. Heat extraction from cold-water sink to condense the working fluid in the condenser.

TURBINE

GENERATOR

COLD DEEP WATER

5 C

WORKING FLUID(LIKE AMMONIA)

CLOSED CYCLE SYSTEMORANDERSON CYCLE SYSTEM

Types

OPEN CYCLE SYSTEM

OR

CLAUDE CYCLE SYSTEM

OPEN CYCLE SYSTEM

OPEN CYCLE SYSTEM SYSTEM

Open-cycle OTEC uses the tropical oceans' warm surface water to make electricity. When warm seawater is placed in a

low-pressure container, it boils. The expanding steam drives a low-

pressure turbine attached to an electrical generator. The steam, which has left its salt behind in the low-

pressure container, is almost pure fresh water. It is condensed back into a liquid by exposure to cold temperatures from deep-

ocean water.

CLOSED CYCLE SYSYTEM

CLOSED CYCLE SYSTEM SYSTEM

Closed-cycle systems( Rankine ) use fluid with a low-boiling point,

such as ammonia, to rotate a turbine to generate electricity.

Here's how it works. Warm surface seawater is pumped

through a heat exchanger where the low-boiling-point fluid is

vaporized. The expanding vapor turns the turbo-generator. Then, cold, deep seawater—pumped

through a second heat exchanger—condenses the

vapor back into a liquid, which is then recycled through the

system.

ADVANTAGESi. Eco- friendlyii. Minimal maintenance costs compared to other

power production plantsiii.Provide air conditioning to buildings within the

OTEC plantiv. Fresh water - first by-product is fresh water. A small

1 MW OTEC is capable of producing some 4,500 cubic meters of fresh water per day, enough to supply a population of 20,000 with fresh water

v. Open cycle OTEC systems can produce desalinated water which is very important in third-world countries

vi.Chilled soil agriculture- cold seawater flowing through underground pipes, chills the surrounding soil. Thereby allowing many plants evolved in temperate to be grown in subtropics due to temp. difference in the plant roots in cool soil and plant leaves in warm air

ADVANTAGES

Vii. Mineral Extraction :

OTEC helps in mining ocean water for 57 trace elements. Most economic analyses have suggested that mining the ocean for trace elements would be unprofitable as so much energy is required to pump the large volume of water needed and because of the expense involved in separating the minerals from seawater. But in OTEC plants already pumping the water, the only remaining economic challenge is to minimize the cost of the extraction process.

DISADVANTAGES

i. OTEC-produced electricity at present would cost more than electricity generated from fossil fuels at their current costs.

ii.OTEC plants must be located where a difference of about 20º C occurs year round. Ocean depths must be available fairly close to shore-based facilities for economic

iii.No energy company will put money in this project because it only had been tested in a very small scale.

iv.Construction of OTEC plants and lying of pipes in coastal waters may cause localized damage to reefs and near-shore marine ecosystems.

SUMMARY1. Based on Rankine cycle -

Thermodynamic cycle which converts heat into work through a heat engine

2. As with any heat engine , the greatest efficiency and power is produced with the largest temperature differences.

3. Uses the vertical temperature gradient in the ocean as a heat sink/source

4. Temperature differences generally increases with decreasing latitude , in the tropics, thereby mainly used in equatorial waters where temperature difference is greatest

FUTUREThe fossil fuels will in the near future be consumed, so we had to find some alternative energy sources. OTEC is a source, which uses the renewable solar collector, the sea, instead of an artificial collector.

The problem is that this investment will be more expensive than the fossil fuels power plants, and it will take a long time before anyone will put some money in this project and outrival the now existing plants.

THANK YOU