3. Geothermal energy is thermal energy generated and
stored in the Earth
The Geothermal energy of the Earth's crust originates
from the original formation of the planet (20%) and
from radioactive decay of minerals (80%).
4. EATRTH AS AN
ENERGY SOURCE
The earth's core maintains temperatures in
excess of 6000°K due to the heat generated by the
gradual radioactive decay of the elements it contains.
5. •Inner Core - The inner core is solid with a radius of about 1,220 km
and consists of about 80% Iron and 5% to 10% Nickel, with a
temperature of up to about 7,200 K
•Outer Core- The outer core, also mainly Iron and Nickel, is in a liquid
state and is about 2,260 km thick. Melted rock is also called Magma
•Mantle is about 2900 kms thick surrounding the core and
contains 83% of the volume and most of the mass of the Earth
•Lithosphere - The lithosphere is defined as the solid rocky region
about 100-200 km thick which spans the crust and the rigid upper
mantle•Crust - The Earth's crust occupies just 1% of the Earth's volume with a
thickness averaging just 15 km
•The temperature at the Earth's surface is typically 25 °C
6. ENERGY USED FROM EARTH IS GENERALLY TWO TYPES
1. HEAT EXCHANGERS
2. POWER PLANT GENERATION
7.
8. There are three types of systems used in power plants in power generation
1. Dry Steam Systems
2. Flash Steam Systems
3. Binary Cycle Power Plants
9. Dry Steam Systems
•Dry steam system is make use of direct steam
That is obtained from aquifer.
•This is by far the cheapest method of
generating electrical energy from
geothermal resources
10. •Superheated water at high
temperature and pressure is
available from many more hot
water aquifers as well as hot rock
systems.
•When the pressure is reduced the
water flashes to steam.
•The most common geothermal
electricity generating plants are
currently flash generators
11. •The hot water circuit is
separated by Heat exchanger
with closed loop circuit of
turbine• The hot water gives up its heat
in the heat exchanger to a
working fluid
•Working fluid has low boiling
point and high vapour pressure
at low temperatures when
compared to steam
•working fluid is typically an organic compound such as
ammonia, butane, pentane or isopentane
•Working fluid circulates through the secondary side of the heat
exchanger where it vaporizes and the vapour is then used to rotate
a turbine in a conventional Rankin electricity generating plant
12. •Geothermal heat pumps are similar to ordinary heat pumps
•Instead of using heat found in outside air ,it uses heat found in
earth
•The earth's constant temperature is what makes geothermal
heat pumps one of the most efficient, comfortable
13. •winter it collects the Earth's natural heat through a series
of pipes, called a loop, installed below the surface of the
ground or submersed in a pond or lake. Fluid circulates
through the loop and carries the heat to the house
•There, an electrically driven compressor and a
heat exchanger concentrate the Earth's
energy and release it inside the home at a
higher temperature.
•In summer, the process is reversed
14. 1.Vertical Ground Closed Loop
2. Horizontal Grounded closed Loop
3. Pond Closed Loop
Here are the typical loop
configurations
15. Vertical Ground Closed Loops
•Vertical holes 150 to 450 feet
deep are bored in the ground
and a single loop of pipe with a U-
bend at the bottom is inserted
•Each Vertical pipe is connected to
Heat exchanger inside the house
•Vertical loops are generally more
expensive to install, but require less
piping
16. Horizontal Ground Closed
Loops
•In this a deep hole is trenched 3 to 6
feet below the ground and a series of
Parallel pipes are arranged and it is
trenched back
•It is most effective
17. Pond Closed Loops
•It is most economical when a home is
near a body of water such as a shallow
pond or lake.
•Fluid circulates underwater through
polyethylene piping in a closed
system, just as it does through ground
loops
•Since it is a closed system, it results in
no adverse impacts on the aquatic
system.
18. •Since a GeoExchange system burns no fossil fuel on-site
to produce heat, it generates far fewer greenhouse gas
emissions than a conventional furnace
•Total emissions in power plant electricity generation
are far lower than for conventional systems
•Carbon monoxide emission is far lower
