Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Energy 201 > Geothermal energy > Flashcards

Geothermal energy Flashcards

1
Q

What is geothermal energy

A

Energy from the earths interior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why is geothermal energy renewable
(kinda weird definition)

A

it is a renewable energy source because heat is continuously transferred from within the earth to the water recycled by rainfall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 layers of the earth

A

core, mantle, crust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the core of the earth composed of

A

inner core - iron center
outer core - magma - radioactive decay generates heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mantle composed of

A

magma and rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how thick is the crust on continents vs under the ocean

A

25-55 km thick on continents
5-8 km thick under oceans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are geothermal hot spots created

A

volcanic activity - magma near tectonic plates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the classifications of geothermal resources

A

hydrothermal
magma
enhanced
geopressurized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe hydrothermal

A

high temperature water in steam, liquid or mixed phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe geopressurized

A

hot-water 150-180 °C under very high pressure, with methane and dissolved solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe magma

A

molten rock under volcanoes at temperatures > 650 °C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe enhanced

A

water injected into hot rocks, generating steam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the process for enhanced geothermal systems

A

1) water is injected at high pressure into hot rock formations
2) The heated water returns to the surface as steam
3) Steam powers turbines for electricity generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the depth and temperature of the rock formation for a enhanced geothermal system

A

3-5 km
hot rock formations can reach to 250 °C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the resource temperature categories and their range

A

low temperature T < 90 °C
medium temperature
90 °C < T < 150 °C
high temperature T > 150 °C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the reservoir states

A

steam dominated and liquid dominated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the difference between the reservoir states

A

steam-dominated has a higher quality with high enthalpy and energy
liquid dominated is more used worldwide and often produced as brine or brine-steam mixture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Geothermal energy involves the ________ use of geothermal water for space, water, and process _________

A

direct
heating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

carrying geothermal water over long distances is not ____-effective

A

cost

20
Q

heating requires geothermal resource temperatures above ___ °C

A

50

21
Q

Which 5 countries lead in geothermal heating

A

china, sweden, iceland, turkey, and USA

22
Q

in iceland, what percent of buildings are heated using geothermal energy

A

90%

23
Q

What is the total annual global space heating using geothermal energy in joules

A

360,000TJ

24
Q

geothermal brine is not directly circulated due to undesirable _________ properties

A

chemical

25
Q

heat exchangers are used to transfer the heat of _________ water to __________ water and this heated _________ water is sent to the district

A

geothermal
fresh
fresh

26
Q

Geothermal heat can be used in _____________ refrigeration systems.
* These systems are feasible for ________ cooling with sufficient annual cooling load.
* ______ initial costs limit the widespread use of geothermal cooling systems.

A

absorption
district
high

27
Q

What temperature does the absorption cooling system operate in

A

100-200 °C.

28
Q

What are the typical refrigerants

A

NH3 and H2O or water-lithium bromide

29
Q

Refrigerant absorption occurs with the help of a _______ _______

A

transport medium

30
Q

The most widley used absorption refrigeration system is

A

ammonia-water system

31
Q

What are other absorption refrigerant system and what is there refrigerant and how is it limiting

A

Water-lithium bromide and water-lithium chloride both have water as a refrigerant and these systems must remain above the freezing point of water. Therefore they are limited to applications such as air conditioning.

32
Q

What are the advantages of geothermal energy sources

A

low operational cost
easy integration with other renewable energy systems
widespread availability
stability and reliability
wide-range operational capacity
fossil fuel-free operation
environmentally friendly
no complicated systems or components

33
Q

What are the disadvantages of GES

A

effects of earthquakes
surface instability
environmental impact due to some harmful emissions
high initial costs

34
Q

What are the classification of geothermal energy applications

A

power generation
heat pumps
other

35
Q

What are the types of power generation for geothermal

A

dry-steam geothermal power production
flash geothermal power production
binary geothermal power production
combined flash/binary geothermal power generation

36
Q

What are the two types of heat pumps

A

heat pump applications
reversible heat pump applications

37
Q

What does the other applications category include. For geothermal

A

absorption cooling applications
hydrogen production
industrial chemical production
drying processes

38
Q

List the 5 steps for geothermal power generation

A
  1. Geothermal energy sources
  2. Steam generation/heat extraction from production well
  3. Power generation cycle
  4. Electricity generation
  5. Water discharge to injection/ reinjection well
39
Q

Can a heat pump be used to heat a house in the winter and cool it in the summer?

A

yes

40
Q

What are the 3 types of ground-source heat pumps

A
  1. Horizontal loop ground-source heat pump
  2. vertical loop ground-source heat pump
  3. ground water wells ground-source heat pump
41
Q

Fill in the blanks:
Overview of horizontal loop ground-source heat pump
* Horizontal piping is buried underground at depths of 1.2 to _____ meters.
* This system is ideal for areas with sufficient _______ for pipe installation.
* Commonly used in homes with ______ backyards.

A

2.0
space
large

42
Q

Do i need a big backyard for vertical loop ground-source heat pump

A

no, it is suitable for areas with limited space

43
Q

What depths does vertical piping range from

A

10 to 250 m

44
Q

Advantages of vertical loop

A

minimal maintenance and operates safely
year-round heating and cooling

45
Q

challenges of vertical loop

A

higher installation costs than horizontal systems
limited capacity per borehole, with lower ground temperatures impacting performance

46
Q

Fill in the blanks:
Overview of ground water wells ground-source heat pump
* Underground water circulates through
the _________ of the heat pump.
* Heat is transferred from the water to the
refrigerant, and ________ water is returned
to the ground.

A

evaporator’
cooler

47
Q

Fill in the blanks:
Overview of ground water wells ground-source heat pump
* Water wells are typically __ to __ meters
deep, offering high _________ at
relatively low cost.
* These systems require ________ for
sufficient water yield, and regular
maintenance
and ______
quality
monitoring are essential.

A

5 to 50
capacities
aquifers
water

Energy 201 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions