A presentation by my friends and I for KC21402 Heat Transfer Chemical Engineering under Dr Fiona Tham on OTEC

1. OCEAN THERMAL ENERGY

2. ADELISA SENTIKA ANAK JUKA
ANGEL KUOK MEI ERH
FATIN NABILA BINTI ISHAK HISHAM
GEETHA BASHNI A/P SANDRISON

3. ENERGY
• Ability to do work
• Anything that can be turned into
heat
• Process of generating electricity from
heat

4. SOLAR ENERGY
• Harness light and heat from the sun
• Active: solar collector uses photovoltaic panels
to convert sunlight
• Passive: build houses from stone or clay
• Advantages: free, pollution free, can be used
in rural area
• Disadvantages: be harnessed during daytime
and sunny, solar panels are expensive, large
areas required

5. GEOTHERMAL ENERGY
• Heat flows from hot interior of the earth
• Volcanoes, hot springs and geysers
• Produce hot water or steam which moves
through cracks in the rock
• Advantages: pollution free, use small area
• Disadvantages: difficult to maintain and repair

6. BIOMASS
• Waste materials being converted into energy
• Waste wood, tree branches, garbage
• Advantages: generate energy, always available
• Disadvantages: expensive, inefficient when
compared to fossil fuels, require more land

7. OCEAN THERMAL ENERGY
• Thermal energy from Sun’s heat and
mechanical energy from tides and waves
• Largest solar collectors (covers more than 70%
of earth surface)
• Warms the surface but not into deep ocean
water
• Temperature difference around 20 degree
celcius can generate energy
• 1000m depth

8. • Relies on the relationship between
pressure, temperature and volume
• When there is difference in
temperature, it can be used to create
an increase in pressure which will be
used to drive turbine

9. Ocean Thermal Energy
Conversion (OTEC)
• Three types of OTEC cycles
–Close cycle
–Open cycle
–Hybrid cycle

10. Close cycle
• Organic Rankine cycle (ORC)
– Operates on principles of evaporation and
condensation of working fluid
– Organic fluid, eg. Ammonia circulates in a closed
loop of the system
– It is more volatile, able to evaporate easily to
saturated vapour, less cost and easier to be
transported

11. ORGANIC RANKINE CYCLE (CLOSE CYCLE)
(AMMONIA)
The turbogenerator then
generates electricity and
mechanical power
Latent heat is released
from the ammonia vapor
to cold sea water from
condenser
Pressure of ammonia is increased

12. Kalina Cycle
• Another close cycle is Kalina cycle
• Has better performance
• Working fluid : ammonia-water mixture
• Condensation and evaporation are allowed to
occur over a range of temperatures at a given
pressure
• Less irreversibilities thus higher efficiency
• A separator and a absorber are installed

13. Separates strong
ammoina vapour
from the weak
solution
Absorbs the strong
ammonia vapour
onto the weak
solution

14. Open cycle
• Claude’s cycle
• Warm sea water as working fluid
• Low pressure of 1% to 3% of atmospheric
pressure (Masutani & Takahashi, 2001)
• Byproduct produced is the desalinated water
discharged as condensate
• Desalinated water can be reprocessed into
potable drinking water

15. Flash
evaporation of
warm sea water
in a partial
vacuum
Expansion of
the steam
through a
turbine to
generate
power
Condensation of
vapour by direct
heat transfer to
cold sea water
Compression and
discharge of
condensate and
any residual
noncondensable
gas
CLAUDE’S CYCLE

16. Hybrid cycle
• Combination of 2 cycles:
– Close cycle
– Open cycle
• First cycle : Close cycle to produce electricity
• Second cycle: Open cycle to produce
desalinated water
• Uses ammonia as working fluid
• Higher efficiency due to this combination

17. Hybrid Cycle

19. - Δ T of at least 20 – 22 degree Celsius
- Surface T: 25 - 30 degree Celsius
-Deep sea T: 3 degree Celsius
- Depth of more than 1000 m

22. Pulau Jambongan (northern coast of Sabah)
Kota Belud
Sibu
Straits of Melacca
Sabah Trough

23. - It one of the most longest Straits with
constant flow
- Average depth : 40 m
- Shallow for OTEC system
- Potential area for tidal energy instead

24. - Studies done by UTM-OTEC
- Depth: 2900 m
- Surface T: 29 degree Celsius
- Deep sea T: 3 degree Celsius
- Up to 50 000 MW

25. BENEFITS AND LIMITATIONS

26. BENEFITS

27. Pollution Control

28. Byproducts can be recycled

29. REFRIGERATION

30. AGRICULTURE

31. MARICULTURE

32. AQUACULTURE

33. ELECTRICITY

34. LIMITATIONS

35. LOCATION

36. Location : Sea

37. Location : Land

38. THANK YOU