Geothermal

Question 1

Geothermal energy

Answer 1

Thermal energy within the earth’s interior

Question 2

Why it is considered re?

Answer 2

Because heat is continuously transferred from the earth to the water recycled by rainfall

Question 3

Interior of the earth is made of:

Answer 3

1-Inner core 6500 km deep (iron center)
2-Outer core made from hot magma with high temps due to decay of radioactive particles
3- mantle, thickness 3000 km made of magma and rocks
4- crust, 25 to 55 km on the continentsand 5-8 km under the oceansmade of tectonic plates - volcanoes occur near the edge of these plates dove to magma getting close to it

Question 4

How we make use of geothermal energy

Answer 4

At some depth, rocks and water absorb heat from magma, these are geothermal resources, by digging wells and pumping hot water to the surface, we use geo.

Question 5

History of geothermal

Answer 5

1- hot springs used for bathing millions years ago..
2- geothermal generated electricity was in that produced Italy 1904.
3- first direct exchange ground - source heat pump in 1940

Question 6

Geothermal energy definition

Answer 6

Thermal energy generated and stored in the earth

Question 7

Thermal energy

Answer 7

Energy that determines the temp of matter, geothermal is heat transferred by conduction

Question 8

Geothermal energy of the earth’s crust originates from?

Answer 8

Original formation of the planet (20%),radioactive decay of minerals (80%)

Question 9

Geothermal gradient

Answer 9

Difference in temp between the core of the planet and its surface, drives continuous conduction of thermal energy in the form of heat from the core to the surface

Question 10

How geothermal occur?

Answer 10

1 - at the core of earth, thermal energy is created by radioactive decay, temps reach 5000C, heat conducts from the core to surrounding cooler rock.
2-high temp and pressure cause some rocks to melt creating magma.
3- magma convection upward because its lighter than solid rocks.
4-magma heat the rocks and water in the crust up to 370C.
5-ground water near dormant volcanois heated by reservoirs of molten rock on 3 km depth.
6- wells are drilled to recover the water, when capturedsteam and hot water are separated - steam is cleaned and sent to the power plant, wateris returned to the reservoir by injection wells.

Question 11

Geothermal energy world status

Answer 11

• geothermal electricity production: US - Philippines - Indonesia
• geothermal direct use: china- US - Sweden

Question 12

Types of technologies and classifications of geo resources

Answer 12

1- high energy: temp between 150-350 C , geothermal electricity production.
2- medium energy: temp between 80-150 C, geothermal direct use, heat.
3- low energy: temp less than 80 C, geothermal direct use heat pumps, use shallow ground to heat or cool buildings.

Question 13

Environmental impacts

Answer 13

1- land: vegetation loss, soil erosion, land slides.
2- air: slight air heating, local fogging.
3- ground: reservoir cooling, tremors.
4- water: watershed impact, damming streams, hydrothermal eruptions, lower water table, subsidence.
5- noise

Question 14

Geothermal potential in Jordan

Answer 14

Jordan is part of the ring of fire, have medium energy (110-114C) and low energy (30-64C) , location of all thermal springs is dead sea rift
Geothermal gradient ,ap of jordan shows two distinct regions of high geo gradients up to 50 C/ km
Wells near queen alia airport, shoneh, maeen thermal spring

Question 15

Geothermal electricity production

Answer 15

Geothermal power plants use steam produces from reservoirs of hot water found below the earth surface to produce electricity

Question 16

Types of geothermal power plants

Answer 16

Dry steam- flash steam (single, double ), - binary cycle

Question 17

Dry steam power plants

Answer 17

Extracted from natural reservoirs / 180-225 C/4-8 Mpa/ 55.5 m/s or 200 km/hr
Steam is used to drive a turbo-generator
Steam is condensed and pumped back into the ground
Can achieve 1 kwh per. 6.5 kg stea

Question 18

Single flash steam power plants

Answer 18

Steam with water extracted from ground.
Pressure of mixture drops at surface and more water flashes to steam.
Steam seperated from water then drives a turbine.
Turbine drives an electric generator.
Generate between 5 and 100 MW
Use 6 to 9 tones of steam per hour to produce mw.
Have brine water to make the evaporation quicker.
When pressur drops, water is pumped, and turbine moves, thats why its called flash

Question 19

Double flash power plants

Answer 19

Unflashed liquid flow into low pressure tank, flashes to steam.
Steam drives a second stage turbine and also use exaust from first turbine.
Increase output 20-25% for. 5% cost increase

Question 20

Binary cycle power plants

Answer 20

Low temp 100-150 C
Use heat to vaporize organic liquid.
Use vapor to drive turbine, vapor condense, recycle continuously.
7-12% efficient.
0.1-40 mw

Question 21

Working fluid in binary power plant

Answer 21

Organic fluid: iso-butane / iso-pentane / ammonia

Question 22

Combined cycle plants

Answer 22

Combination of conventional steam turbine and binary cycle.
Steam drives primary turbine, remining heat used to create organic vapor, organic vapor drives a second turbine.
Size from 10 to 100 mw
Greater efficiency, higher urilization, extract more power and heat from geo resource

Question 23

Hot dry rock technology

Answer 23

Wells drilled 3-5 km into crust, hot crystalline rock formations.
Water pumped into formations.
Water flows through natural cracks. (Formations) picking up heat.
Hot water/ steam returns to surface.
Steam used to generate power

Question 24

Geothermal direct use for sources between. 80-150 C

Answer 24

Space heating
Air conditioning
Aquaculture
Drying
Greenhouses
Industrial processes.
Hot water.
Resorts and pools.
Melting snow

Question 25

District heating

Answer 25

Apps sited near source (<10 km)
Direct sources function by sending water down a well to be heated by the earths warmth.
Then the heat pump iS used to take heat from underground water to the substance that heats the house, then after the water is cooled its injected back into earth (hot dry rock).

Question 26

Heat source

Answer 26

47% of the Solar energy falling on our planet is absorbed by the earth’s surface maintaining a nearly constant temp throughout the year just below ground.

Question 27

Basic principles in winter

Answer 27

Geothermal heat pump transfers underground heat to provide heating to the building.

Question 28

Basic principles in summer

Answer 28

Geothermal heat pump transfers heat from the building into the ground to provide cooling

Question 29

Geo heat pump

Answer 29

Circulates water through sealed under ground piping loop where its naturally warmed or cooled by earth
Circulate water in normal climates
Circulate anti freeze/ water mixture im cold climates

Question 30

Reasons to use a heat pump

Answer 30

Environmental benefits: reduce kwh/m2 and co2 in kg/yr
Operating costs: less than normal electricity costs
Security for the future

Question 31

Installation methods

Answer 31

1- vertical closed loop
2- horizontal closed loop

Question 32

Vertical closed loop

Answer 32

Pair of pipes with special assembly at the bottom is placed into boreholes from. 30 to 120 m deep

Question 33

Horizontl closed loop

Answer 33

Piping array is installed 1 to 1.5 m deep and hundreds of meters in length.