Chapter 6 - Geothermal Flashcards
Refers to the internal heat from the earth
Geothermal
A rock-forming crystalline mixed silicate which constitute about 60% of the earth’s earthquake
Feldspar
A compound rock, a crypto - crystalline form of silica which is dens, tough, breaking with a conchoidal fracture
Flint
The process of using injection wells to bubble air through groundwater
Sparging
A popular term used by utilities to mean upgrading existing plant
Repowering
A dense, fine grained, light colored igneous rock which is rich in silica
Felsite
An opening in lava or in volcanic area through which steam and other hot gases are escaping into the air is called:
Fumarole
Tidal power is the power generated from:
rise and fall tides
Converts chemical energy directly into electrical energy
Fuel cell
Generates a voltage from incident light, usually light in the visible region
Photovoltaic Cell and Solar Cell
All of the following terms are synonymous with quanta of electromagnetic theory except
X-rays
In geothermal power plants waste water is:
Discharged back to earth
In a liquid-dominated geothermal plant, what process occurs when the saturated steam passes through the turbine
Polytropic
What do you call a conversion technology that yields electricity straight from sunlight without the aid of a workinv substance like gas or steam without the use of any mechanical cycle?
Photovoltaic-energy conversion
Tidal power plant is attractive because it has:
Cheap energy source
The statement that the product of the error in the measured determination of a particle’s position and its momentum is of the order of Planck’ constant h is known as:
The Heisenberg uncertainty principle
The flow process through shock wave is highly irreversible and cannot be approximated as being:
Isentropic
Beaufort scale is used for measuring?
Wind speed
Betz law is widely used in?
wind mills
Rocks having excessive internal stresses may produces spalling. This rocks are called _____
stratified rocks
Solar energy arrives at the outside of the earth’s atmosphere at an average rate of _____
1.354 kW/m²
How many percent of solar energy survives absorption and reflection?
40 to 70%
Solar energy is capturesld in:
Solar collector
Which of the following solar collectors are essentially wide, flat boxes with clear plastic or glass coverings known as glazing?
Flat plate collectors
Which of the following collectors use mirrors and lenses to focus the suns energy on a small absorber area?
Concentrating collectors
Which of the following collectors are more complex, but their efficiencies are higher?
Evacuated Tube collectors
Useful when extremely hot transfer fluid is needed and are generally limited to commercial projects
Evacuated tube collectors
The shading factor in calculating the heat absorbed by the solar collector has a value of approximately:
0.95 to 0.97
Ratio of energy absorbed by the transfer fluid to the original incident energy striking the collector
Collector efficiency
The difference between the ambient air and inlet temperature increases, what happens to the collector efficiency?
Decreases
Distributee collector is also known as:
trough electric system
Central receiver system is also known as:
Power tower system
Which of the following main approaches to solar energy generating systems describes that parabolic tracking trough concentrators focus sunlight on evacuated glass tubes that run along the collector focal lines?
Trough electric system
Trough electric technology due low temp. average annual thermal efficiencies are only:
10-15%
A field of heliostats or travking mirrors concentrares solar energy to a receiver on a central tower
Power tower system
Power tower system typical thermal efficiencies :
15 - 20%
Dish engine system efficiency
24 - 28%
Practical and economic issues limit trough electric systems about:
200 MW
Practical and economic issues limit TOWER electric systems to approximately:
100 - 300 MW
Thermal efficiency of a geothermal power plant
22%
Flash steam cycle can be used if the hot water temperature is:
165 °C or higher
A binary cycle using a separate heat transfer a fluid if the temperature of the hot water is between ________
165 °C and 120 °C
For every kilometer of depth the temperature of the earth’s crust increase by
30 F
Multiple wells produce steam at 690 to 830 kPa and temp. of ______
205 °C
In hot rock systems, water is injected through injection wells into artificially made fractured rock beds of how many kilometers below the surface?
1 to 6 km
